There are many known processes for recovering dissolved copper values from solutions containing same and most of these are concerned with the recovery of copper values from pregnant leach solutions derived by leaching sulfide copper ore material with a weak sulfuric acid lixiviant. The most commonly employed process in this connection is the so-called "cementation" of metallic copper on metallic iron employed as a precipitant, followed by pyrometallurgical and electrolytic purification of the precipitated copper.
There have been no truly radical technological changes or advances in several decades in this field and only incremental improvements in existing methods and adaptations of other types of technology to mining have gradually reduced costs and increased productivity.
In the past several decades, little emphasis was placed on environmental impact left by copper mining. The process left the tailings with unsafe environmental chemicals which re-enter the earth's natural drain and water systems with the leached tailings being in a condition and of a size which cannot be used for other purposes.
Also, in the past, mining interests were concerned with only large deposits and were satisfied to remove less than 60 percent of the copper present and were satisfied economically with the return on their investment. However, in recent years, mining interests are taking a second look at smaller deposits, low grade deposits, mine tailings, and waste dumps with an attempt to find solutions to comply with extensive environmental regulations related to air, water, and soil quality with better material handing and disposal practices.